Anti-Japan protests have been expanding and escalating in China. This is a serious situation.

Protesters railing against the recent nationalisation of three islets of the Senkaku Islands in Ishigaki, Okinawa Prefecture, by the central government have taken to the streets of about 100 cities in China.

In Beijing, protesters hurled rocks at the Japanese Embassy, while in other cities they attacked Japanese-affiliated business establishments. Some Japanese citizens have been assaulted in places where there have been no street demonstrations.

It is quite reasonable for Prime Minister Yoshihiko Noda to have lodged a protest with the Chinese government. The Japanese government must continuously press China to ensure the safety of Japanese citizens and businesses and the protection of their property.

The Chinese government should strictly punish those involved in behaviour that results in property destruction in accordance with the law.

In parallel with these protests, there have been aggressive acts by the Chinese government itself, which is apparently trying to undermine Japan's control of the Senkaku Islands.

Unprecedented intrusion

In an unprecedented action, six Chinese government maritime surveillance ships intruded into Japanese territorial waters near the Senkaku Islands on Friday at the same time.

This is the first time that China has raised tensions with Japan to such a stage since bilateral diplomatic relations were normalized in 1972.

China has probably acted out of a heightened sense of crisis that it may lose face if the administration under the Chinese Communist Party is perceived by the people to have conceded to Japan over the Senkaku islets.

In China, a Foreign Ministry spokesperson said Japan's "wrongful act" (nationalisation of the three islets) has been provoking strong righteous indignation in China, showing Beijing's sympathy for the anti-Japan protests. A senior Commerce Ministry official has also implied a boycott of Japanese products would be a natural consequence.

Such developments have fueled the anger of a younger generation that has been immersed in patriotic education, causing an escalation of their actions.

The Chinese government has apparently decided to politically exploit the people's anger against the Japanese government's nationalization of the Senkaku Islands to exert diplomatic pressure on Japan.

Maintain the rule of law

But for the Chinese government to sanction illegal behaviour under a slogan that a patriotic act should not be considered a crime would be to deny the rule of law. And boycotting products of a specific country violates the spirit of free trade, which also runs counter to China's interests.

Appeals are being made for people to demonstrate against Japan again on Tuesday, which marks the 81st anniversary of the Liutiaohu Incident that triggered the Manchurian Incident. It is feared the daily activities of Japanese people and businesses in China may be badly affected again.

It is highly likely that a fleet of Chinese fishing boats, escorted by fishing monitoring vessels of the Chinese agriculture ministry, will soon leave ports for the Senkaku Islands shortly and try to intrude into Japanese territorial waters.

The Japanese government, for its part, must make absolutely sure that the Japan Coast Guard protects the territorial waters.

The government must assert to the international community that the Senkaku Islands are Japanese territory and that the recent acquisition of the islands is intended to place them under stable government management.

The national leaders of Japan and China should bring the current situation under control so as not to aggravate the conflict of their people's sentiments.